Answer:
19 °C
Explanation:
Step 1: Given and required data
- Mass of granite (m): 20 g
- Heat absorbed (Q): 300. 2 J
- Specific heat capacity of granite (c): 0.790 J/g.°C
Step 2: Calculate the temperature change (ΔT)
We will use the following expression.
Q = c × m × ΔT
ΔT = Q/c × m
ΔT = 300.2 J/(0.790 J/g.°C) × 20 g = 19 °C
A lone oxygen atom has 6 electrons in its outer shell which is not very stable, whereas as full octet (8 outer shell electrons) is stable. In order to achieve this two oxygen atoms will share 4 electrons, each contributing 2 electrons. Since these electrons exist within the orbitals of both atoms, to oxygen atoms essentially achieve a full octet.
Solution :
a). 
This compound is known as sulfur trioxide.
The molecular shape of sulfur trioxide is trigonal planer.
And the bond angle is 120°.
b). 
This compound is known as Nitrous oxide. Here, nitrogen is in the center. There is no lone pair around the nitrogen atom and it forms two sigma bonds with the other two atoms.
It is linear in shape.
The bond angle between them is 180°.
c). 
This compound is known as the Dichloromethane.
The molecular shape of the compound is tetrahedral.
The bond angles is 120°
<h2>Natural Abundance for 10B is 19.60%</h2>
Explanation:
- The natural isotopic abundance of 10B is 19.60%.
- The natural isotopic abundance of 11B is 80.40%.
- The isotopic masses of boron are 10.0129 u and 11.009 u respectively.
For calculation of abundance of both the isotopes -
Supposing it was 50/50, the average mass would be 10.5, so to increase the mass we need a more percentage of 11.
Determining it as an equation -
10x + 11y= 10.8
x+y=1 (ratio)
10x + 10y = 10
By taking the denominator away from the numerator
we get;
y = 0.8
x + y = 1
∴ x = 0.2
To get percentages we need to multiply it by 100
So, the calculated abundance is 80% for 11 B and 20% 10 B.
Ans: The entropy change for the given reaction is 93.3 J/K
Given reaction:
Br2(l) → Br2(g)
ΔS = ∑n(products)S⁰(products) - ∑n(reactants)S⁰(reactants)
= 1 mole* S°(Br2(g)) - 1 mole*S°(Br2(l))
= 1 mole *245.5 J/mol-K - 1 mole*152.2 J/mol-K
= 93.3 J/K
